Multi-contact rotary electric switch with resiliently biased conductive pins



j Y E N 9 m 5 s, .E m M F E m, .M m lu s Hm F .M NP I E ww. www www1 C.wl-Amma OED e YEn 4 ERM@ .und G RMR H Tum.. MN .o 5 Tm wm Cs MULTI..

May 18, 1965 yf., y L ji United States Patent O MULTI-CONTACT ROTARYELECTRIC SWITCH WITH RESILIENTLY BIASED CNDUCTIVE PINS Robert FrederickOxley, Priory Park, Ulverston, England Filed .lune 5, 1961, Ser. No.114,849

Claims priority, application Great Britain, June 7, 1960,

1 Claim. (Cl. 200-11) This invention relates to rotary switches. Suchswitches may be used for many purposes for selectively completing anumber of different circuits.

It is an object of the invention to provide a rotary switch of simpleconstruction and one which enables many different connections to beeasily made from outside of the switch. It is another object of theinvention to provide a rotary switch which can be of small size.

According to the present invention a rotary switch comprises a sleevehaving a wall, one or more series of radially disposed conductive pinsarranged on a circumference and extending through said wall, a switchingmember mounted for rotation within said sleeve about the axis of saidsleeve, and conducting means mounted on said switching member forselective engagement with at least one pin or with at least one pin fromeach of said series. The sleeve may be polygonal but is preferablycylindrical.

Preferably each of the pins is resiliently secured in a hole in thesleeve. One way in which this can be achieved is for each pin to extendthrough a resilient insulating bushing secured in a hole in the sleeve.

One example of the invention and a modification thereof will now bedescribed with reference to the accompanying drawing, in which:

FIGURE 1 is a longitudinal section of the rotary switch;

FIGURE 2 is an end view of the rotary switch in the direction indicatedby the arrow II shown in FIGURE l;

FIGURE 3 is a cross section on the line lll-III in FIGURE l; and

FIGURE 4 is a cross-section similar to FIGURE 3 of a rotary switch ofthe same general construction as that shown in FIGURES 1 to 3 but inwhich the pins are secured in the sleeve in a different manner.

As illustrated in FIGURES l, 2 and 3, the rotary switch comprises a bodyhaving two cylindrical portions 11 and 12 spaced by a hexagonal portion13. The smaller diameter cylindrical portion 11 is screwthreaded and therotary switch may be secured in a panel by entering this portion througha hole in the panel and tightening a nut on 'the screwthread. A sealingring 14 is provided to ensure hermetic sealing between the hexagonalportion 13 and the panel.

The body 10 carries a coaxial spindle 15 to the outer end 16 of which aknob may be attached for rotating the spindle. At its inner end thespindle carries an index plate 17 which rotates with the spindle. Theindex plate 17 has twelve evenly spaced apertures 18 arranged around acircle and these apertures may be engaged by a pair of balls 19 whichare carried in axial drillings 20 in the body 10. The balls 19 arebiased towards the index plate and into the apertures 1S by springs 21contained in the drillings 20 and the thrust on the spindle produced bythe springs is taken by a nylon washer 22 between a ange 23 on thespindle and a shoulder 24 in the body 10. The spindle 15 is alsoprovided with two circumferential grooves 25 which accommodate sealingrings 26 which seal the bore in the body 10.

Secured to the larger diameter cylindrical portion 12 of the body 10 isa rigid sleeve 30 the open end of which is closed by a block 31 ofpolytetrailuoroethylene 3,l84,559 Patented May 18, 1965 (P.T.F.E.). Thesleeve is provided with four circumferential rings of evenly spacedapertures, the apertures also being arranged in axial rows. Eachaperture contains a bored bushing of P.T.F.E. and comprises acylindrical portion 51 of the same diameter as the apertures and aflange 52. The cylindrical portion passes through the aperture from theinside of the sleeve 30 and the flange rests against the inside of thesleeve. Into each bushing is passed from the inside a pin 57 of metal,for example silver-plated brass, and of circular cross section. Each pinhas a central portion 53 of slightly greater diameter than the bore inthe bushing 50 and an outer end portion 54 of approximately the samediameter as the central portion. At the inner end of the central portion53 there is a wedge-shaped tlange 55 while between the central portion53 and the outer end portion 54 there is a similar but slightly largerwedge-shaped ange 56. The pin 57 is pushed into the bore of the bushingfrom inside the cylinder until the inner enlargement 55 lies partlywithin the flange 52 of the bushing and in this position thewedge-shaped flange 56 between the central portion and the end portionof the pin will lie within the cylindrical portion 51 of the bushing onthe outside of the sleeve 39 and will expand the bushing so that thebushing cannot be withdrawn into the cylinder. Fittings of thisdescription are described and claimed in United States Patent No.2,911,460 to Robert Frederick Oxley, dated November 3, 1959,

For the sake of simplicity, only two bushings S0 and associated pins 57have been shown in FIGURE 3 but it is to be understood that there are,in fact, twelve such pins and bushings in the series shown in FIGURE 3.Each of the other three rings of apertures in the sleeve 39 likewiseaccommodates a series of twelve associated pins and bushings.

The lower end (as viewed in the drawing) of the spindle 15 carries aswitching member 32 which consists of a generally cylindrical block of PTFE. and which rotates with the spindle. Extending through the switchingmember are four diametrical drillings 33 whose axes are respectively inthe planes of the series of pins and bushings. Adjacent end of adjacentpairs of drillings 33 accommodate the ball-shaped ends 34 of dumb-bellshaped conducting members 35. Each end 34 is biased radially outwards bymeans of a spring 36 which is contained Within the respectivediametrical drilling 33. Each diametrical drilling 33 thus contains twosprings 36 which are separated from one another by an insulating block37.

The switching member 32 is provided with three radial flanges 40, 41 and42 which engage the ilanges of the adjacent rings of bushings and helpto locate the switching member.

Suitable external connections are made to the projecting end portions 54of the pins 57. It will be seen that in any rotational position of theswitching member 32 in which the balls 19 engage in apertures in theindex plate 1'7 four pairs of pins 57 will be interconnected but ot'course it is not necessary for external connections to be made to allthe pins and accordingly a large number of combinations of circuits canbe selected by the rotary switch described.

The rotary switch illustrated in FIGURES l to 3 may be modified byforming the sleeve 30 from resilient insulating material such asP.T.F.E. and dispensing with the bushings 50. In such a modifiedembodiment which is illustrated in FIGURE 4, the pins are presseddirectly into the sleeve 30 which retains the pins by virtue of its ownresiliency.

Many modifications of the constructions illustrated may be made. Forexample only one or more than two conducting members 35 may be providedfor interconnecting pins from adjacent series and the conducting membersmay take many different forms.

What I claim as my invention and desire to secure by Letters Patent is:

A sealed miniature rotary switch comprising a housing including anopen-ended cylindrical side wall member and end Walls closing the openends of said side wall member to form a closed cylindrical chamber, oneof said end walls having means for securing said housing to a supportingpanel, said side wall member having a plurality of apertures of circularsection extending through it, the apertures being arranged in at leasttwo spaced series, each said series comprising at least twelveapertures, the longitudinal axes of the apertures of each series lyingin a common plane perpendicular to the longitudinal axis of saidcylindrical side wall member and being radial with respect to thelongitudinal axis of said cylindrical side wall member, each aperturecontaining a bushing, each said bushing having a base, a head portiontoo large to pass through the aperture and engaging the inner wallsurface of said cylindrical side wall member around the aperture and areduced portion which extends through the aperture and part of whichprojects outwardly beyond the outer wall surface of said cylindricalside wall member, each said bore having an elongated electricallyconductive pin extending through it, each pin having a head portionengaging the head portion oi the respective bushing, a circumferentialenlargement lying within said part of the reduced portion of therespective bushing which projects beyond the outer wall surface of isaid cylindrical side wall mc'nber and expanding the said part toprevent radially inward movement of the respective bushing through theaperture in which it lies, and a terminal portion which extends radiallyoutwardly beyond the radially outer end of the respective bushing; and arotor including a rotary shaft mounted for rotation in the end wall ofthe housing having said securing means, sealing means sealing betweensaid shaft and said end wall, a cylindrical rotor of insulating materialrigidly secured to said rotary shaft within said closed cylindricalchamber, said closed cylindrical chamber and said rotary shaft and saidrotor being coaxial, axially cxtending grooves in the outer cylindricalsurface of said rotor, an elongated conductive member in each of saidgroove, and spring means urging said conductive members radiallyoutwards of the rotor into selective contact with the heads of saidpins.

References Cited by the Examiner UNITED STATES PATENTS 2,418,616 4/ 47Batcheller 20D-6 2,599,314 6/52 Bobb 20C- 166 2,774,812 12/56 Clark174-153 2,911,460 1l/59 Oxley 174--153 FOREIGN PATENTS 600,344 4/48Great Britain. 827,984 2/60 Great Britain.

BERNARD A. GILHEANY, Pri/'nary Examiner.

MAX L. LEVY, Examiner.

